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Journal ArticleDOI

Observation of Ultra-narrow Electromagnetically Induced Transparency and Slow Light using Purely Electronic Spins in a Hot Atomic Vapor

TL;DR: In this article, the EIT windows were obtained for purely electronic spins in the presence of Doppler broadening and the positive role of collisions was emphasized through measurements of the power dependence of EIT resonance.
Abstract: Electromagnetically induced transparency (EIT) is observed in gaseous 4He at room temperature. Ultra-narrow (less than 10 kHz) EIT windows are obtained for the first time for purely electronic spins in the presence of Doppler broadening. The positive role of collisions is emphasized through measurements of the power dependence of the EIT resonance. Measurement of slow light opens up possible ways to applications.
Citations
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Journal ArticleDOI
TL;DR: In this paper, the effect of coherent diffusion on key Raman processes, namely, Raman spectroscopy, slow polariton propagation, and stored light, are reviewed in this Colloquium.
Abstract: Coherent diffusion pertains to the motion of atomic dipoles experiencing frequent collisions in vapor while maintaining their coherence. Recent theoretical and experimental studies on the effect of coherent diffusion on key Raman processes, namely, Raman spectroscopy, slow polariton propagation, and stored light, are reviewed in this Colloquium.

49 citations

Journal ArticleDOI
TL;DR: The results definitely prove that the lifetime of the cavity photons is governed by the group velocity of light in the cavity and not its phase velocity.
Abstract: We investigate experimentally the lifetime of the photons in a cavity containing a medium exhibiting strong positive dispersion. This intracavity positive dispersion is provided by a metastable helium gas at room temperature in the electromagnetically induced transparency (EIT) regime, in which light propagates at a group velocity of the order of 10000 m/s. The results definitely prove that the lifetime of the cavity photons is governed by the group velocity of light in the cavity, and not its phase velocity.

32 citations

Journal ArticleDOI
TL;DR: Goldfarb et al. as discussed by the authors showed that it is possible to use optically detuned resonances (Fano-like profiles) to see a transition from slow light to negative group velocity.

18 citations

Journal ArticleDOI
TL;DR: In this paper, the authors experimentally and theoretically study two different tripod configurations using metastable helium, with the probe field polarization perpendicular and parallel to the quantization axis, defined by an applied weak magnetic field, and observe destructive interference between the two dark resonances inducing an extra absorption peak at the line center.
Abstract: We experimentally and theoretically study two different tripod configurations using metastable helium ({sup 4}He*), with the probe field polarization perpendicular and parallel to the quantization axis, defined by an applied weak magnetic field. In the first case, the two dark resonances interact incoherently and merge together into a single electromagnetically induced transparency peak with increasing coupling power. In the second case, we observe destructive interference between the two dark resonances inducing an extra absorption peak at the line center.

16 citations

Dissertation
27 Nov 2019
TL;DR: In this article, the propagation of quantique de lumiere is investigated in the presence of coherentness coherentes of populations ultrafines and montre qu'elles permettent de stocker efficacement a quadrature specifique d'un champ lumineux.
Abstract: Un etat quantique de lumiere est caracterise par la statistique de son nombre de photons. Lorsque qu'un champ electromagnetique se propage dans un milieu, ses statistiques peuvent etre modifiees, notamment en presence de phenomenes coherents. Cette these s'interesse experimentalement et theoriquement a la propagation d'etats quantiques de lumiere dans une vapeur d'helium metastable a temperature ambiante. Dans un premier temps, on etudie la propagation de lumiere en presence d'oscillations coherentes de populations ultrafines et montre qu'elles permettent de stocker efficacement une quadrature specifique d'un champ lumineux. Neanmoins, ce protocole ne permet pas de stocker les deux quadratures d'un mode du champ electromagnetique, et les conditions de propagation dans le milieu degradent leurs proprietes statistiques, empechant son utilisation pour des applications quantiques. Ce travail montre ensuite qu'il est possible de generer des etats comprimes a deux modes dans ce meme systeme, par melange a 4 ondes. Les etats fortement comprimes (9 dB) peuvent etre generes en exploitant les fortes non-linearites induites par piegeage coherent de population via une transition optique, ainsi que par la proximite d'une autre transition optique voisine. Enfin, une derniere partie s'interesse au transfert de bruit par effet Faraday entre les fluctuations de spin atomique du milieu et les fluctuations de polarisation d'un champ lumineux. L'etude de ces fluctuations par spectroscopie de bruit de spin a mis en evidence des comportements originaux qui pourraient par la suite etre utilises dans d'autres milieux.

15 citations

References
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Journal ArticleDOI
TL;DR: An experiment is reported in which a light pulse is effectively decelerated and trapped in a vapor of Rb atoms, stored for a controlled period of time, and then released on demand.
Abstract: We report an experiment in which a light pulse is effectively decelerated and trapped in a vapor of Rb atoms, stored for a controlled period of time, and then released on demand. We accomplish this ``storage of light'' by dynamically reducing the group velocity of the light pulse to zero, so that the coherent excitation of the light is reversibly mapped into a Zeeman (spin) coherence of the Rb vapor.

1,651 citations

Journal ArticleDOI
TL;DR: In this paper, small group velocities of order 90 m/s and large group delays of greater than 0.26 ms were observed in an optically dense hot rubidium gas ( $\ensuremath{\approx}360\mathrm{K}$).
Abstract: We report the observation of small group velocities of order 90 m/s and large group delays of greater than 0.26 ms, in an optically dense hot rubidium gas ( $\ensuremath{\approx}360\mathrm{K}$). Media of this kind yield strong nonlinear interactions between very weak optical fields and very sharp spectral features. The result is in agreement with previous studies on nonlinear spectroscopy of dense coherent media.

1,042 citations

Journal ArticleDOI
TL;DR: It is demonstrated that stimulated Brillouin scattering can be used to generate all-optical slow-light pulse delays of greater than a pulse length for pulses as short as 16 ns in a single-mode fiber, and strongly suggest that analogous delays can be achieved using stimulated Raman scattering at telecommunication data rates.
Abstract: We demonstrate a technique for generating tunable all-optical delays in room temperature single-mode optical fibers at telecommunication wavelengths using the stimulated Brillouin scattering process. This technique makes use of the rapid variation of the refractive index that occurs in the vicinity of the Brillouin gain feature. The wavelength at which the induced delay occurs is broadly tunable by controlling the wavelength of the laser pumping the process, and the magnitude of the delay can be tuned continuously by as much as 25 ns by adjusting the intensity of the pump field. The technique can be applied to pulses as short as 15 ns. This scheme represents an important first step towards implementing slow-light techniques for various applications including buffering in telecommunication systems.

868 citations

Journal ArticleDOI
TL;DR: Low group velocities of light in an optically dense crystal of Pr doped Y2SiO5 are reported by using a sharp spectral feature in absorption and dispersion that is produced by resonance Raman excitation of a ground-state spin coherence.
Abstract: We report ultraslow group velocities of light in an optically dense crystal of Pr doped ${\mathrm{Y}}_{2}{\mathrm{SiO}}_{5}$. Light speeds as slow as 45 m/s were observed, corresponding to a group delay of 66 \ensuremath{\mu}s. Deceleration and ``stopping'' or trapping of the light pulse was also observed. These reductions of the group velocity are accomplished by using a sharp spectral feature in absorption and dispersion that is produced by resonance Raman excitation of a ground-state spin coherence.

791 citations

Journal ArticleDOI
TL;DR: The first experimental studies of the temporal dynamics and spatial behavior of propagating EIT pulses are reported, including the observation of nearly diffractionlimited beam transmission in a medium which, without the coupling laser present, is nearly optically impenetrable.
Abstract: We describe the temporal and spatial dynamics of propagating electromagnetically induced transparency pulses in an optically thick medium. Results include pulse velocities as slow as $c/165$ with 55% transmission, strong-probe-field effects, and the observation of near diffraction-limited transmitted beam quality.

541 citations